Study On Compressive Strength Of Micro-jet Grouting Columns By Physical Modeling

Document Type : Research Article


1 Department of Civil Engineer, Science and Technology University

2 School of Civil Eng.; Iran University of Science and Technology; Tehran; Iran


Jet grouting method is considered as one of the most widely used improvement methods among the others and is applicable in most geotechnical problems such as increasing bearing capacity, reducing settlement, creating seals, stabilizing slopes, etc. One of the challenges faced by designers is finding the strength and geometry of the elements made using this method. The most effective components in the resistance of jet grouting columns are the type and parameters of injection, soil characteristics (such as aggregation), the amount of cement inside the sample, water to cement ratio of slurry, the type of cement and the method of sampling (coring or wet sampling). In this paper, after the construction of small scale jet grouting columns (micro jet grouting volumns) in the laboratory and taking core of them, the impact of various factors such as the effect of construction speed, the position and direction of coring, as well as the effect of coring operation on unconfined compressive strength is studied. Also, the point load test was used to study more about the strength parameters of the microjet grouting columns. Based on the results, the compressive strength of microjet grouting columns is high (approximately up to 59 MPa), and these values are confirmed by the point load test. It was also observed that with increasing speed of soil-cement columns construction, compressive strength decreases. Based on the compressive strength results, it is found that coring operation reduces resistance by 60%. Also, the cores taken in the horizontal direction showed about 33% less uniaxial compressive strength than the vertical cores and cores taken from the upper parts of the columns have more compressive strength.


Main Subjects

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